Gaseous electric discharge lamp device



May 26, 1936. c. 50L

Q GASEOUS ELECTl RIC DISCHARGE LAMP DEVICE Filed May 25, 1934.

INVENTOR ATTORNEY Patented May 26, 1936 GASEOUS CTRIC DISC DEVICE Cornelis Bol, Einoven, Netherlands, assignor to General. Electric Company, a corporation of New York Application May 25, 1934, Serial No. 727,527 In the Netherlands June 3, 1933 2 c. (or. zit-11.4)

The present invention relates to gaseous electric discharge lamp devices generally and more particularly the invention relates to lamp units comprising such devices.

Gaseous electric .discharge lamp devices having a gaseous filling comprising a metal vapor,

. particularly the vapor of a difficultly vaporizable metal, such as sodium, thallium, magnesium, or zinc usually require a heat conservator in order to reduce the radiation of heat from thecontainer of the device and thus obtain an efiective metal vapor pressure. A suitable heat conservator is a double-walled glass jacket having the portion thereof touches the inner wall of the vessel. A cold spot is thus created on the lamp container wall which lowers the vapor pressure in the lamp and deleteriously affects the emciency thereof.

The object of the present invention is to provide a' lamp unit of the above type in which the above ditficulties are avoided. Still further objects and advantages attaching to the device and to its use and operation will be apparent to those skilled in the art from thefollowing particular description.

In accordance with this object the invention 35 comprises a centering element for the container of said device in said heat conservator. The bottom part of the heat conservator is indented and the'curved part of said container has a protuberance thereon, the centering element fits into 40 said indentation and around said protuberance to maintain said'container in its proper position in said conservator and contact between the lamp container and the heat conservator is thus pre vented.

In the drawing accompanying and forming part of this specification an embodiment 'of the invention is shown in a front elevational, partly sectional view.

Referring to the drawing the new and novel lamp unit comprises a gaseous electric discharge lamp device having a U-shaped tubular container. Said container i has a gaseous filling therein consisting of a rare gas, such as neon, and a metal vapor, such as sodium, a pair oi electrodes consisting of a filamentary cathode which is electron emitting when heated and an open ended cylindrical anode surrounding said cathode is sealed into each end of. said container i. Said container l is mounted 'in a heat conservator in the form of a double walled glass jacket 3 having the space 4 between the walls thereof evacuated or filled with a gas having poor heat conductivity characteristics. Said jacket 3 reduces the radiation of heat from the container i to maintain an eifective metal vapor pressure in said container I during the'operation of said lamp device. The container I is provided with a base 2 made of heat resisting, insulating material,

such as asbestos cement, and said base 2 is cemented to one end only of said container l. The other end of said container I is free to move with respect to said base 2 so that the expansion and contraction of saidcontainer I when the lamp is turned on and off does not cause the container I. to break under the physical strains thus set up. The jacket 3 is supported by ring 5 cemented thereto which makes a tight mechanical joint with said base 2 as shown in the drawing.

At the bottom of said jacket 3 is a cylindrical indentation into which is inserted a cylindrical support element I made of material having poor thermal conductivity characteristics, such as glass. The support element I is fastened to the exhaust tip of the container I by a body 8 of cement inserted in said element I and surrounding said exhaust tip. The container I is thus centered andsupported in said jacket 3 by the element I and the end of said container I cemented to said base 2. Contact between the wall of container I and the inner wall of said jacket 3 with all the attendant disadvantages pointed out heretofore is thus avoided.

What I claim as new and desire to by Letters Patent of the United States is:-

1. A lamp unit comprising in combination, a gaseous electric discharge vapor lamp having a curved, tubular container, the ends of said oontainer being in adjacent positions,a base attached to one end of said container, the other end of said container being free to move in said base, a heat conservator for said vapor lamp, said conservator being removably aflixed to said base and a tubular centering support element of heat insulating material attached to the curved part of said container, said conservator having a cylindrical indentation therein opposite the curved part of said container to accommodate said tubular support, said support being movable along the length of said cylindrical indentation to permit expansion and contraction of said container and being immovable laterally of said cylindrical indentation to support said container away from the walls of said conservator.

2. A lamp unit comprising in combination, a gaseous electric discharge vapor lamp having a U-shaped, tubular container, the endsof said container being in adjacent positions,- a base accommodating both ends of said container and attached to one'end of said container,'the other end of said container being free to move in said base, a double walled-heat conservator for said vapor lamp, said conservator being removably affixed to said base and a tubular centering supportelement of heat insulating material mounted on the curved part of said container, the inner wall 01 said conservator having a cylindrical indentation therein opposite the curved part of said container to accommodate said tubular support, said support being movable along the length of said cylindrical indentation to permit expansion and contraction of said container and being immovable laterally of said cylindrical indentation to support said container away from th walls of said conservator.

' CORNELIS BOL. 

